PT - JOURNAL ARTICLE AU - ULISSE CUCCHI AU - LAURA M. GIANELLINI AU - ANNA DE PONTI AU - FRANCESCO SOLA AU - RACHELE ALZANI AU - VERONICA PATTON AU - ALICE PEZZONI AU - SONIA TROIANI AU - MARIA B. SACCARDO AU - SIMONA RIZZI AU - MARIA L. GIORGINI AU - PAOLO CAPPELLA AU - ITALO BERIA AU - BARBARA VALSASINA TI - Phosphorylation of TCTP as a Marker for Polo-like Kinase-1 Activity <em>In Vivo</em> DP - 2010 Dec 01 TA - Anticancer Research PG - 4973--4985 VI - 30 IP - 12 4099 - http://ar.iiarjournals.org/content/30/12/4973.short 4100 - http://ar.iiarjournals.org/content/30/12/4973.full SO - Anticancer Res2010 Dec 01; 30 AB - Polo-like kinase 1 (PLK1) is the master regulator of mitosis and a target for anticancer therapy. To develop a marker of PLK1 activity in cells and tumour tissues, this study focused on translational controlled tumour protein (TCTP) and identified serine 46 as a site phosphorylated by PLK1 in vitro. Using an antibody raised against phospho-TCTP-Ser46, it was demonstrated that phosphorylation at this site correlates with PLK1 level and kinase activity in cells. Moreover, PLK1 depletion by siRNA or inactivation by specific inhibitors caused a correspondent decrease in phospho-TCTP-Ser46 signal validating this site as a direct marker of PLK1. Using this marker, the study characterized PLK1 inhibitors in cells by setting up a high-content assay and finally immunohistochemical assay suitable for following inhibitor activity in preclinical tumour models and possibly in clinical studies was developed.